Added gzip middleware

Signed-off-by: Vishal Rana <vr@labstack.com>

Author: vishr

README.md

@@ -91,7 +91,7 @@ func main() {
 	e := echo.New()
 
 	// Middleware
-	e.Use(mw.Logger)
+	e.Use(mw.Logger())
 
 	// Routes
 	e.Get("/", hello)

context.go

@@ -53,8 +53,8 @@ func (c *Context) Param(name string) (value string) {
 
 // Bind binds the request body into specified type v. Default binder does it
 // based on Content-Type header.
-func (c *Context) Bind(v interface{}) *HTTPError {
-	return c.echo.binder(c.Request, v)
+func (c *Context) Bind(i interface{}) *HTTPError {
+	return c.echo.binder(c.Request, i)
 }
 
 // Render invokes the registered HTML template renderer and sends a text/html
@@ -69,10 +69,10 @@ func (c *Context) Render(code int, name string, data interface{}) *HTTPError {
 }
 
 // JSON sends an application/json response with status code.
-func (c *Context) JSON(code int, v interface{}) *HTTPError {
+func (c *Context) JSON(code int, i interface{}) *HTTPError {
 	c.Response.Header().Set(ContentType, ApplicationJSON+"; charset=utf-8")
 	c.Response.WriteHeader(code)
-	if err := json.NewEncoder(c.Response).Encode(v); err != nil {
+	if err := json.NewEncoder(c.Response).Encode(i); err != nil {
 		return &HTTPError{Error: err}
 	}
 	return nil

echo.go

@@ -90,7 +90,9 @@ const (
 	//---------
 
 	Accept             = "Accept"
+	AcceptEncoding     = "Accept-Encoding"
 	ContentDisposition = "Content-Disposition"
+	ContentEncoding    = "Content-Encoding"
 	ContentLength      = "Content-Length"
 	ContentType        = "Content-Type"
 	Authorization      = "Authorization"

examples/crud/server.go

@@ -61,7 +61,7 @@ func main() {
 	e := echo.New()
 
 	// Middleware
-	e.Use(mw.Logger)
+	e.Use(mw.Logger())
 
 	// Routes
 	e.Post("/users", createUser)

examples/hello/server.go

@@ -17,7 +17,7 @@ func main() {
 	e := echo.New()
 
 	// Middleware
-	e.Use(mw.Logger)
+	e.Use(mw.Logger())
 
 	// Routes
 	e.Get("/", hello)

examples/middleware/server.go

@@ -21,7 +21,7 @@ func main() {
 	//------------
 
 	// Logger
-	e.Use(mw.Logger)
+	e.Use(mw.Logger())
 
 	// Basic auth
 	e.Use(mw.BasicAuth(func(u, p string) bool {
@@ -41,6 +41,9 @@ func main() {
 
 	//	e.Use(mw.RedirectToSlash())
 
+	// Gzip
+	e.Use(mw.Gzip())
+
 	// Routes
 	e.Get("/", hello)
 

examples/web/server.go

@@ -65,7 +65,7 @@ func main() {
 	e := echo.New()
 
 	// Middleware
-	e.Use(mw.Logger)
+	e.Use(mw.Logger())
 
 	//------------------------
 	// Third-party middleware

middleware/auth.go

@@ -14,7 +14,7 @@ const (
 	Basic = "Basic"
 )
 
-// BasicAuth provides HTTP basic authentication middleware.
+// BasicAuth provides HTTP basic authentication.
 func BasicAuth(fn AuthFunc) echo.HandlerFunc {
 	return func(c *echo.Context) (he *echo.HTTPError) {
 		auth := c.Request.Header.Get(echo.Authorization)

middleware/compress.go

@@ -0,0 +1,43 @@
+package middleware
+
+import (
+	"compress/gzip"
+	"io"
+	"strings"
+
+	"github.com/labstack/echo"
+)
+
+type (
+	gzipResponseWriter struct {
+		io.Writer
+		*echo.Response
+	}
+)
+
+func (g gzipResponseWriter) Write(b []byte) (int, error) {
+	return g.Writer.Write(b)
+}
+
+// Gzip compresses HTTP response using gzip compression scheme.
+func Gzip() echo.MiddlewareFunc {
+	scheme := "gzip"
+
+	return func(h echo.HandlerFunc) echo.HandlerFunc {
+		return func(c *echo.Context) *echo.HTTPError {
+			if !strings.Contains(c.Request.Header.Get(echo.AcceptEncoding), scheme) {
+				return nil
+			}
+
+			w := gzip.NewWriter(c.Response.Writer)
+			defer w.Close()
+			gw := gzipResponseWriter{Writer: w, Response: c.Response}
+			c.Response.Header().Set(echo.ContentEncoding, scheme)
+			c.Response = &echo.Response{Writer: gw}
+			if he := h(c); he != nil {
+				c.Error(he)
+			}
+			return nil
+		}
+	}
+}

middleware/compress_test.go

@@ -0,0 +1,42 @@
+package middleware
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"compress/gzip"
+	"github.com/labstack/echo"
+	"io/ioutil"
+)
+
+func TestGzip(t *testing.T) {
+	req, _ := http.NewRequest(echo.GET, "/", nil)
+	req.Header.Set(echo.AcceptEncoding, "gzip")
+	w := httptest.NewRecorder()
+	res := &echo.Response{Writer: w}
+	c := echo.NewContext(req, res, echo.New())
+	Gzip()(func(c *echo.Context) *echo.HTTPError {
+		return c.String(http.StatusOK, "test")
+	})(c)
+
+	if w.Header().Get(echo.ContentEncoding) != "gzip" {
+		t.Errorf("expected Content-Encoding: gzip, got %d", w.Header().Get(echo.ContentEncoding))
+	}
+
+	r, err := gzip.NewReader(w.Body)
+	defer r.Close()
+	if err != nil {
+		t.Error(err)
+	}
+
+	b, err := ioutil.ReadAll(r)
+	if err != nil {
+		t.Error(err)
+	}
+	s := string(b)
+
+	if s != "test" {
+		t.Errorf(`expected "test", got "%s"`, s)
+	}
+}